A look at what's new, bountiful or mysterious in the produce aisles:

Red plums, next to crimson plums with a rosy blush, next to black plums, next to hybrids in yellow-green. . . . Their variety is prodigious in July, August and September, peak months for the stone fruit.

Plums can be surprising. Will the one you sink your teeth into be tart or sweet? There are no guarantees, but there are a few hints.

Most of what you'll find in stores now are kinds of so-called Japanese plums (cultivated long ago in China but first chronicled by Western botanists in Japan). They are juicy and generally round, although some are heart-shaped with a pointed end. They run from reds to purples with red or yellow flesh and are most often eaten without adornment.

Familiar names of this type that you'll find on the fruit's labels include El Dorados, Elephant Hearts, Presidents and Red Beauts. Santa Rosas are perhaps the most widely known and commercially marketed in the country. They were bred by horticulturalist Luther Burbank (1849-1926) in California, where more than 90 percent of commercially grown U.S. plums are from. You might also come across tree-ripened red plums, which tend to run a bit larger.

Dragon plums, which have been spotted at Harris Teeter stores, are actually Pluots, the combo fruit first engineered in California in 1989 that is 75 percent plum and 25 percent apricot. They are yellow-green inside and out and are markedly sweeter than red plums.

At roadside stands lately, we've come across smaller, round plums that are not much bigger than cherries, with pits that pop right out.

The other major type of plums is the slightly oval, smaller and darker European-style variety or plum native to Europe, with flesh that changes from a tart red to a mellower yellow when they're ripe. They have thicker, more bitter skins and are easier to pit. Their names include Damson and Mirabelle, also at their peak now, and prune or Italian plums, which will arrive in stores in the fall. The darker plums are best for baking and for making preserves, jams and the plum sauce that accompanies Chinese food. Mirabelle plums are used to make wine and brandy.

To tell if a plum is sweet, author and food scientist Shirley O. Corriher suggests sniffing the end opposite the stem. It should have a full, fruity aroma.

HOW TO SELECT: Choose plums that have smooth skin with no cracks. If you're in the market for dark-red plums, look for ones with a natural bloom -- the powdery cast often means they've been minimally handled. They should be slightly soft at the stem and tip but otherwise fairly firm. They will ripen once you get them home. The fruit will get juicier as it softens, but not necessarily sweeter.

HOW TO STORE: Remove plums from any plastic bags; store them in an uncovered bowl. Ripe plums will keep in the refrigerator for four or five days. To ripen them faster, place plums in an unrefrigerated paper bag with a few holes punched in it.

HOW TO PREPARE: Wash plums in cool water before eating. Room temperature is best for plums eaten out of hand. Tarts are usually made with fall's Italian plums.

-- Bonnie S. Benwick